【作者】 康七虎；

【导师】 宋考平；

【作者基本信息】 大庆石油学院 ， 油气田开发工程， 2008， 博士

【摘要】 大庆深层火山岩气藏具有埋藏深、温度高的特点,试气施工难度大,大多数气井采用地面开关井方式进行施工。在气井压力恢复过程中,井筒中存在的较大温度变化影响着气井井底压力恢复动态,造成气井试井评价中压力恢复曲线异常,均质无限大地层会呈现出复合油藏或双孔地层特征,掩盖了储层真实特征,而现有的试井模型没有考虑井筒温度变化,使得到的试井分析结果合理性准确性受到影响。针对上述生产实际问题,根据热力学知识,对气井不同生产状态下井筒内温度的变化规律、温度对气体物性参数的影响规律进行分析与研究。应用热力学相关理论,建立气井井筒温度变化模型。结合气井渗流理论,建立了考虑热效应影响的气井试井渗流数理模型。根据数理模型,建立有热效应影响的试井理论图版,并结合理论图版对气井的热效应影响规律进行分析,判断气井井筒温度对试井分析压力曲线的影响情况,研制开发出一套考虑热效应影响的气井不稳定试井评价软件。对试井曲线异常的气井资料进行考虑热效应影响的试井解释,给出气井地层渗透率、表皮系数及井筒最大影响温差等参数。应用14口井18层气井资料对研究的试井分析方法进行检测与验证,经验证模拟产能与实际产能误差均小于20%。应用解释结果对6口已经投产的气井进行中长期产能预测,与气井实际生产情况进行对比与验证,有5口井模拟产量与实际产量相符,证明考虑热效应影响气井试井方法解释的参数更加准确地反映气井真实储层性质。在实际气井资料试井分析工作中效果良好,达到了准确评价有热效应影响气井试井资料,正确认识与评价储层,指导深层气井勘探开发的目的。更多还原

【Abstract】 The volcanic gas reservoir of Daqing has the characteristic of deep burial and high temperature. The gas well testing in the reservoir is difficult, and most of the wells are operated by surface open and shut-in method. During the process of pressure buildup, the larger temperature change existed in the wellbore affects the downhole pressure buildup dynamics, and causes the abnormity of pressure buildup curve in well testing evaluation. The homogeneous infinite reservoir will present composite or double porosity characteristics, and the true features of the reservoir are disguised. As the present well testing model does not consider the wellbore temperature change, the rationality and accuracy of the well testing results are affected. To solve the above problems, based on the thermodynamics knowledge, the temperature change law inside the wellbore under different production status, and the effect law of temperature on gas property parameter are analyzed and studied. Applying the related theory of thermodynamics, the temperature change model in the gas wellbore is established. Based on the seepage flow theory of gas well, the mathematical logic model for gas well testing is established considering the thermal effect. And in accordance with the mathematical logic model, the well testing theory plate under the thermal effect is established. The thermal effect law on gas well is analyzed on the basis of the theory plate to distinguish the effects of temperature inside the gas well on pressure curves, The transient well testing evaluation software of gas well is developed considering the thermal effect. The gas well data with abnormal well testing curves are interpreted by the software with the consideration the thermal effect, the parameters, such as, the formation permeability, skin factor, and the maximum temperature differential effect in the wellbore, etc, are given.The method is inspected and verified with the data from 14 wells and 18 layers. The error of simulated productivity is less than 20% compared with the real productivity. To compare with the real well productivity and test the simulated results, in 6 producing wells, the simulated results are applied to predict the medium and long term productivity. The simulated results of 5 wells are consistent with the real production, which demonstrates the parameters given by the well testing method considering the thermal effect reflect more accurately the real reservoir properties. The better results of the method shown in the real gas well testing analysis attains the goal of evaluating accurately gas well testing data with thermal effect, understanding and evaluating the reservoir correctly, and guiding the exploration and production of the deep gas well.更多还原